Protocol offload transmit traffic management

1. A method of operating a network interface device to facilitate the transfer of data between at least one application, operating on a host, and a peer, the transfer of data encapsulated in packets according to a particular communication protocol, the network interface device communicatively coupled to the host, the method comprising: receiving, from the application, data destined for transmission to the peer via the network; protocol processing with the peer, by a protocol mechanism operating according to the particular communication protocol and based at least in part on an indication of a desired transmission rate characteristic, to encapsulate the data received from the host into packets such that the packets are provided from the network interface device to the network with the desired transmission rate characteristics; wherein the protocol processing with the peer is controlled by a transmission rate regulating mechanism operating based on an amount of data to be transmitted and on the desired transmission rate characteristics, to regulate a rate at which the protocol processing mechanism operates with respect to the data, to encapsulate the data into packets and to cause the packets to be output from the network interface device to the network.

2. The method of claim 1 , wherein: the peer is a particular peer; and the protocol processing mechanism is configured to operate a plurality of connections between the host and a plurality of peers including the particular peer; the connections are grouped into a plurality of categories; and the protocol processing step includes protocol processing for each connection with at least one of the plurality of peers such that, for each connection, the protocol processing for that connection by the protocol processing mechanism is based at least in part on a desired transmission rate characteristic for the category to which that connection belongs, to encapsulate the data received from the host for that connection into packets such that the packets are provided from the network interface device to the network with the desired transmission rate characteristic for the category to which that connection belongs.

3. The method of claim 2 , wherein: at least some of the indications of desired transmission rate characteristics indicate at least one of a group consisting of at least one desired shaping characteristic and at least one desired pacing characteristic.

4. The method of claim 3 , wherein: the transmission rate regulation mechanism operates, for each connection, based on an estimate of an amount of data to be transmitted for that connection and the desired transmission rate for the category to which that connection belongs, to regulate a rate at which the protocol processing mechanism operates for that connection to encapsulate the data for that connection into packets to be transmitted to the network.

5. The method of claim 4 , wherein: the transmission rate regulation mechanism further operates, for each connection, according to a priority associated with the category to which that connection belongs.

6. The method of claim 5 , wherein: the priorities associated with the categories are based at least in part on an amount of data to be transmitted for the separate categories.

7. The method of claim 1 , wherein: the protocol processing step includes processing information received from the network and, based in part thereon, controlling the protocol processing step.

8. The method of claim 1 , wherein: the protocol processing step includes processing information received from the network, and, the method further comprises determining whether transmission of particular data to the peer should not be deferred, based on a result of processing the information received from the network.

9. The method of claim 8 , wherein: the protocol processing step includes TCP, and determining whether transmission of particular data to the peer should not be deferred includes processing the information received from the network to determine if at least part of the data to be transmitted to the peer has previously been transmitted.

10. The method of claim 9 , wherein: if it is determined that at least part of the data to be transmitted to the peer has previously been transmitted, determining that the transmission of the particular data to the peer should not be deferred.

11. A network interface device configured to facilitate the transfer of data between at least one application, operating on a host, and a peer, the transfer of data encapsulated in packets according to a particular communication protocol, the network interface device communicatively coupled to the host, the method comprising: means for receiving, from the application, data destined for transmission to the peer via the network; and means for protocol processing with the peer, operating according to the particular communication protocol and based at least in part on an indication of a desired transmission rate characteristic, by encapsulating the data received from the host into packets such that the packets are provided from the network interface device to the network with the desired transmission rate characteristics; wherein the means for protocol processing with the peer is controlled by a transmission rate regulating mechanism operating based on an amount of data to be transmitted and on the desired transmission rate characteristics, to regulate a rate at which the protocol processing mechanism operates with respect to the data, to encapsulate the data into packets and to cause the packets to be output from the network interface device to the network.

12. A network interface controller configured to facilitate the transfer of data between at least one application and a peer via a network using a protocol processing mechanism, wherein data destined for the peer is provided from the at least one application, operating on a host, for transmission to the peer via the network, the data encapsulated in data packets formed using the protocol processing mechanism, according to a particular transmission protocol, comprising: means for managing a data structure of tokens, each token including an estimate of an amount of data in the data packets to be transmitted, managing the data structure including retrieving tokens out of the data structure based on the included estimate of an amount of data in the data packets to be transmitted and based on desired data transmission rate characteristics; protocol processing means for protocol processing with the peer, for each token retrieved out of the data structure by the protocol processing mechanism according to the particular transmission protocol, by encapsulating data provided from the at least one application into a data packet and to cause the data packet to be transmitted to the peer via the network, such that data packet transmission to the peer via the network is modulated to nominally have desired data transmission rate characteristics; and means for feeding back a result of the protocol processing step to cause a token to be stored into the data structure of tokens.